Bringing the car up to mod level with a normal FBO would be first, and temper expectations for hunting the GTR From what I can tell the XI is a good 6mph down on traps to a similarly modded 335i all other things being equal. I equate this to drivetrain loss and the extra 250lbs it carries.

The suspension seemed to help a lot with BobVadar, who's got the fastest 335xi 6MT, I'm not sure if he has a 2-step setup but that might be nice to have as well. Also I often wondered if it would be worthwhile to try and do what the evo guys do, and find a way to run motorcycle slicks on the car instead of installing regular drag slicks...not sure about that one being that the 335xi probably weighs a good 600lb more. Of course if you end up having to buy half-shafts, that will be pricey for both axles, but since the rear takes the brunt of the torque maybe it would be OK just doing the rear if they break.

I'll be watching how this goes, if someone gets VTT stage 3 to fix on an XI and it does OK I may sell my 6AT 335xi and buy a 6MT (assuming no 6AT solution arrives).

excuse my ignorance but what can the 335xi transfer case handle to date wtq wise? that'd be my main concern. the few examples of the e46 xi w/FI has failed miserably and that was at ~3rd of the torque VTT3 offers

Personally I'd think about a used set of RBs, really good clutch and maybe some weight reduction (battery, wheels, maybe even brakes). I think the axles will hold up since the power is split x4 but the transfer case has a known problem where the worm gear that applies force to the clutches in there just gets eaten up with a lot of abuse.

A guy with the name "Jack M." on E90poop with a shop that does a lot of transfer case upgrades for other platforms said he was working on upgrading but's been silent for a bit. I can't bring myself to link E90poop here but go to the XI section and look up the thread titled "Transfer Case Upgrade Possibilities". Page 8 in particular has good info and a picture of a chewed up worm gear for the Tcase.

How serious is your bro about going more than 500AWHP? Starts to get real pricey after that point.

excuse my ignorance but what can the 335xi transfer case handle to date wtq wise? that'd be my main concern. the few examples of the e46 xi w/FI has failed miserably and that was at ~3rd of the torque VTT3 offers

We don't know yet, but there are shops ready to take it on if people start breaking them. That shouldn't stop anybody.

Bringing the car up to mod level with a normal FBO would be first, and temper expectations for hunting the GTR From what I can tell the XI is a good 6mph down on traps to a similarly modded 335i all other things being equal. I equate this to drivetrain loss and the extra 250lbs it carries.

The suspension seemed to help a lot with BobVadar, who's got the fastest 335xi 6MT, I'm not sure if he has a 2-step setup but that might be nice to have as well. Also I often wondered if it would be worthwhile to try and do what the evo guys do, and find a way to run motorcycle slicks on the car instead of installing regular drag slicks...not sure about that one being that the 335xi probably weighs a good 600lb more. Of course if you end up having to buy half-shafts, that will be pricey for both axles, but since the rear takes the brunt of the torque maybe it would be OK just doing the rear if they break.

I'll be watching how this goes, if someone gets VTT stage 3 to fix on an XI and it does OK I may sell my 6AT 335xi and buy a 6MT (assuming no 6AT solution arrives).

realistically, FBo knowing a stg 3 is going on, what is there to do? FMIC and meth kit right?

GTR hunting is a long term goal, but a 700hp 335 SHOULD be more than enough for a 600hp gtr.. should.. higher than that and built motor territory.

the lack of xi data is why im asking around. I see it as more of a less than favorable conditions, ie driver/setup/commitment for a 6mph difference

excuse my ignorance but what can the 335xi transfer case handle to date wtq wise? that'd be my main concern. the few examples of the e46 xi w/FI has failed miserably and that was at ~3rd of the torque VTT3 offers

Personally I'd think about a used set of RBs, really good clutch and maybe some weight reduction (battery, wheels, maybe even brakes). I think the axles will hold up since the power is split x4 but the transfer case has a known problem where the worm gear that applies force to the clutches in there just gets eaten up with a lot of abuse.

A guy with the name "Jack M." on E90poop with a shop that does a lot of transfer case upgrades for other platforms said he was working on upgrading but's been silent for a bit. I can't bring myself to link E90poop here but go to the XI section and look up the thread titled "Transfer Case Upgrade Possibilities". Page 8 in particular has good info and a picture of a chewed up worm gear for the Tcase.

How serious is your bro about going more than 500AWHP? Starts to get real pricey after that point.

As ,uch as I liek RB's, and what they offer, its not enough for what i want to take this car to. ive been there already. They make great power, but capped. This car will be dedicated project car, and see how far we can take it

Would be awesome to get some data here since it will be a dedicated project car. Mine is my DD, so I would prefer not to be the one leading the way on exploding TCs to find limits as I bump up to non-crap gas on the single this summer.

you may want to hold out a little while and see what becomes of the HPF twin scroll single kit. If they can get if finished and working, a single, twin scroll turbo is going to be the best bet for this platform.

realistically, FBo knowing a stg 3 is going on, what is there to do? FMIC and meth kit right?

GTR hunting is a long term goal, but a 700hp 335 SHOULD be more than enough for a 600hp gtr.. should.. higher than that and built motor territory.

the lack of xi data is why im asking around. I see it as more of a less than favorable conditions, ie driver/setup/commitment for a 6mph difference

Saw someone didn't like my comment above, nice

As far as performance mods, same as a 335i.

One note on the suspension, I would for sure wait to upgrade it until after I did the big mods, and see how it launches stock, sometimes that squishy suspension can be good for weight transfer to the rear wheels. On the XI there was a guy running drag slicks on his rear wheels at the track, not sure if that lowered his 60' or not but kind of an interesting idea.

I'm trying not to bug idspeedskater on e90post too much, but he's the only one with a high WHP 335xi right now that I know of and the vbox numbers are sparse. He has done some running of it on the vbox (60-130 9.26 on a 0.7% upslope) but no 1/8 or 1/4 traps so not really sure what his car is capable of in the 1/4 mile. He would be the best to follow seeing as his car should be making ~560-570awhp on a dynojet from his 519awhp mustang run.

On a downslope he could be in the mid to low 8.x range, which is about right for the loss % on a 335xi. That will help you run with tuned GTRs from a roll for sure, add another 100whp to that and you should be comfortably in the 7.x range especially if you lighten the car down ~250-300lbs (Seats, battery, exhaust, low fuel, lightweight 17'' wheels).

As ,uch as I liek RB's, and what they offer, its not enough for what i want to take this car to. ive been there already. They make great power, but capped. This car will be dedicated project car, and see how far we can take it

Thanks for the insight about the transfer case stuff

NP. If it's a project car and not a DD then it makes sense re RB's being a cap where you're going.

RBs is enough to beat most GTRs you meet on the highway. You won't need an XI to do it either.

If 700HP is your goal and beating GTRs is a side note, I'd def get with HPF. Maybe he can get in as a beta tester.

Since the goal was for an XI I'm guessing he wants to focus on drag strip races. The mags list the newer GTR as running low 11's stock so maybe highway rolls might be doable but that's going to take a a lot of work and power just to get an XI to run high 10's.

Since the goal was for an XI I'm guessing he wants to focus on drag strip races. The mags list the newer GTR as running low 11's stock so maybe highway rolls might be doable but that's going to take a a lot of work and power just to get an XI to run high 10's.

i dont see a big difference in drag racing and XI setups. what works for one, can easily work for the other, besides gearing